摘要：The increased population density, coupled with changes in dietary habits in developing countries towards high quality food and the increasing use of grains for livestock feed is projected to increase demand for food production by 70% by 2050. Crop yields would continue to grow but at a slower rate than in the past. Yield growth will play an important role as only a slow expansion of agricultural land is expected. Future yield increases on lands currently supporting high production levels must come from continued yield enhancing genetic modifications. The most important grain and feed is maize. Genetic improvement has not only contributed to yield increases but also to other desirable plant components such as resistance to lodging and tolerance to increased plant populations, insects, and diseases. Maize production has increased from 200 million tons in 1960 to over 800 million tons in 2011 but has not changed very much recently. The reviews suggest that the overall assessment of farm-level costs and benefits of GM maize has severe limitations. Nonetheless, GM maize is a potential tool to increase farmers’ income and thus might contribute to poverty reduction and sustainable social and rural economic development, especially in developing countries. The results support the contention that the adoption of GM maize leads on average to a higher economic performance, i.e., benefits, for farmers than conventional (non-GM) crops. An important finding of the analysis is that the kind and magnitude of benefits are heterogeneous across crops, traits, countries and regions. However, while the literature on the economic impact of GM crops has grown in recent years there is still a need for more comparative studies across space and time in order to pin down these impacts and allow for a better assessment of the contribution that this technology can make to sustainable development.
